Popping noise from turbo coolant reservoir?

[Birdoprey]

So far i've put 10,000 mi on the new motor in my 2013 X5 50i with out any issues. Mostly drive it normal but romp on it pretty hard every now and then. Today i drove it 120 ish miles(mostly highway, with some in town and several full throttle romps). No issues till i was a almost home. Was on the interstate and got on it pretty hard from 70mph to about 100ish then Engine malfunction/reduced power mode pops up. Backed off and exited the interstate and the warning went away. Pulled up to the house and killed it. A couple of min after killing it i noticed a popping noise kinda like overheated fluid. Popped the hood and the noise seemed to be coming from the coolant reservoir for the turbo/intercooler system right in the center of the motor up front. I didn't want to remove the cap incase the fluid was overheated.

Any ideas what could be the issue? I've been searching but i'm not coming up with anything as of yet.

[Ryan5034]

When my turbo pump quit working I got a different warning on the dash. Doesn't hurt to check the fluid levels of both coolant bottles.

Might take the engine cover off and look for a coolant leak. Lots of little lines on top. Use a flashlight so you can look in the valley of the engine.

That said not sure what popped the reduced power message my guess is something else is wrong.

I assume you have new coils and plugs since your engine was new?

[TKR]

Easy check for the turbo coolant pump is to drive it next time normal, not too hard. And when you turn it off you should heard a quiet humming/whirring pump noise from for 10mins after engine shut off. Open the hood and you'll hear it easier. The pump is under the small turbo-line reservoir. If you drive it hard the main fan will run 10mins after shut off and you can't hear the turbo pump.

If there is complete silence, The pump is not working and the coolant might be boiling if you drive it hard.

[Birdoprey]

I checked the fluid in the turbo coolant tank once it cooled down and it was full. I did notice the engine coolant tank was low. About two pints low. It has never been low before. I did not see any leaks. Drove it the next morning and when i checked the engine coolant tank again and it was less than a pint low. Still not seeing a leak.
I'm afraid the turbo coolant pump may not be working. The popping noise i was hearing sounded like it would when coolant is overheated. I'll check it tomorrow to see if i can hear the pump running. I wonder what kinda fun it is to replace...?

[Ryan5034]

If indeed the turbo pump is bad, it's only a $75 part and you can change it in an hour or so. Make sure you have BMW coolant on hand.

[Birdoprey]

Well, ran into town for a couple of errands and back(20mi round trip). Parked it and popped the hood. There was a light hum coming from under the turbo coolant reservoir. Also the line feeding both turbos was vibrating like fluid was flowing. Pulled the cap and the fluid was where it should be and just barely warm to the touch. Let it cool for an hour or so and checked the engine coolant reservoir. Its right where i left it a couple of days ago. Dunno why all of the sudden it was a little low. Topped it and it was slightly low the next day. Topped it and now it has stayed put for past two days(drove it 120mi yesterday). No funny noises. Of course i've not gotten on it hard either.